find the missing terms and write the rules

Answer:
2. 18, 20, 24, 30, 38, 48
3. 55, 54, 51, 46, 39, 30, 19
4. 3, 9, 27, 81, 263
5. 82, 81, 78, 73, 66, 57
6. 105, 100, 90, 75, 55
7. 10, 15, 21, 28, 36
8. 3, 7, 19, 55, 163, 487
9. 4, 6, 10, 18, 34, 66
10. 7, 17, 27, 37, 47, 57